Convertible aircraft



G. P. HERRICK CONVERTIBLE AIRCRAFT Aug. 8, 1950 5 Sheets-Shae}; 1,

Filed June 1, 1945 INVENTOR.

K K W L n R N w n WA M m G Aug. 8, 1950 G. P. HERRICK ,5

CONVERTIBLE AIRCRAFT I Fil ed June 1, 1945 v 5 Sheets-Sheet 2 70 7/ 87 mmvrolr GERARD R HERE/CK A TTORNEX? 1950 e. P. HERRICK 2,518,008

CONVERTIBLE AIRCRAFT Filed June 1, 1945 5 Sheets-Sheet 3 INVENTOR- GERARD HERE/CK BY 23 M H v 239 l B 235 ATTURNEYj 8, 1950 G. P. HERRICK 2,518,008

CONVERTIBLE AIRCRAFT 5 Sheets-Sheet 4 Filed June 1, 1945 INVENTOR. GERARD P HERR/CK ATTORNEYS 1950 G. P. HERRICK 2,518,008

' CONVERTIBLE AIRCRAFT Filed June 1, 1945 5 Sheets-Sheet 5 11A 523 i i 202 33/ E 322 323 IN V EN TOR. GERARD P HERR/CK BY v A TTORNEYF Patented Aug. 8, 7195 'GeraI' ti'PI'I irrick, New York, N. Y. v Applicationalunel, 1945, Serial No. 596,987

My inventionnrelates to.multiple flight com rtib-lesaircrafh H zgMoreeparticularly ,my invention relates-. to. i a eavienthan air aircraft which is operable either start-helicopter;drivengrotorl craft an auto-rozl'tatingroton crafttorgas a fixedsuriace planeand orisgconvertible.vwithg certainty and safety from a:eitheretypeaofacrait to. the; other while in theair. In other words, it is capable of taking off, flying and landing jin -any-; of the three types of flight mentionedras well as being convertible from one ,theiother-while; in the air. 7 x I .plnrny prior Patent No.; 1,'792,014 issued Febru- 1ary;;.- 10, 1931, I lave-v shown. a l convertible craft 1,;whic isoperable and convertible while in the air L. irom lafixed. surface planetoan auto-rotating rotor-rcraft. The-practicability of the craftillusigrated.inthat patent has been demonstrated by thexbuildingof.a full size machine, and repeated {oflights taking ofi fiying and landing as an airyrpla firbakin t-fl in an a d n l e rotating craf t and. converting" from. airplane 'fiight-to auto-rotating'flight inthe air. f'j

However, the aircraft built .underi my prior patentgwa s inqapable, of'op'eration asia' helicQpter ,'-and.- as incapable of conversion while irttlfijelairlto bnfrom a lhelicopteror' from an autorotating craftflto. a fixed surfacefltylieplane'and hereforefits usefulness was lir'nitedfflFor exampl, itdid not include "the important'tfeatiires of .vertical take-ofhhigh speed efficient fixed wing ,Yflightifollowing such take-61f and f hovering and ..,.ve cal (landing. The-craft of resent inenti on .enibodies all of these important features F i additionfgtol those iincliidefdin myprior'patent whereby;ithe].advantagesof the speed andfe fii- -.;ciency=offthe'airplane is combined in ajs'ingle machinewith.the. safety and convenience of the rotating wing'inachinc. Y'Ihe' craft of my present"inventionalso emf bodies improvements over thefixed Surfaceblane and auto rotatingi rotor features of my prior W lt-Qfj 'Oneobject of the"inventionis-ahombined helicopter driven rotor and auto-rotating rotor-craft.

"surface. craft capable of sustained flight as either oof said types of craft and. readily convertible from aonetype to the other. V

: A further object of the invention is a novel and improved combined helicopter driven rotor and .i.csfixed surface craft capable ofsustained flight as either type of craft and readily convertible from eithentypeofzcraftto the other. u

A further object of the -invention is :a convertible; craft. ot; the character above indicated 5 embodying oppositely rotatable lifting surfaces, and a further; object issuch a craft: embodying anovel and improvedrotor controlv 1 l A;furtherrobjectaof the inventionliswa com- :bined rotary and fixed surface craft readily con- 10 V =vertib1e-iroin. one ,typeof craft to the other wherein. certain of the controls are utilized for both rotary and-fixed surf ace. operation. i

A further object of the invention is a combined rotary. j and .fixed surfacercraft convertible from the rotaryto the fixed surface type while in the airq-withra conversion control assuring sustaining lift of the. craft during such. conversion. A further object of the invention is a combined l rotary and fixedl surface cr'af't' capable of conversion from' either type to" the other and of sustaining fiightas eithertype, includingnovel and ,irnpiovddcontrobmeans while operating as jeithertypl. f I c v p v I A flirtherlobject. -oftheinvention is a combined 25,;jrotam and; fixed surface ,craft. capable of ready conversion from either type to the other.) and 5. sustaining flight ,as either type and including nove l and improved converting means, andnovel ;and .improved control means 'for controlling the craft'ldurin g eithertjype ofnoperaltion.

l furtherlobjectof..theinvention is a combined rotary" and "fixed surface craft. convertible] from either type. totheother and including'novel and i mprovedmeans for arresting, orienting and 1001;- 5 1mg. the. surface inifixed operating position.

further.,object of the invention is a combined rotaryand fixed surface craft convertible from either type 'to .the o therand includingmeans 'responsive'tofthe. conversion ineans for variation A ru'rther object othe inv'e tionisa craft of the albove indicated.character and control therefor; mbodyif-igj a single control elementby the gmagnipmaffi n of which converting operations inaylwbeflreadily,efieotdl and in the'desi'red order. ;A;:f1 1rtneri object .ofl-the invention is derail; :5 embodying. oppositely". rotating isurfacesjvvith Ineans.fo varying the torque of, onesurfac'ejiivith I resp e'c tztolthefother surface; for control.

A; furthenobjectbf the invention isla noveland na provedfla'riding gear.

.Further objects .of the viilljjher'ein- '7 I understandifigl of invention @f rseq w h tm ma yaed g is Fig. 4 is a diagrammatic view partly in crosssection illustrating the drive for the convertible lifting surfaces and controls;

Fig. 5 is a section along the line 55 of Fig. 4; Figs. 5a and 5b are views of the locking means for the convertible lifting surfaces;

Fig. 6 is a diagrammatic view illustrating th adjusting means for the control of the upper wing;

Fig. 7 is a diagrammatic view illustrating certainnf the controls and converting means ,draTwn along the line 'I-'! of Fig. 8;

Figs. 7a and 7b illustrate details of the structure shown in Fig. '7;

Figs. 8 and 8a diagrammatically illustrate certain features of the controls;

Fig. 9 illustrates a modification of the craft;

Fig. 10 isa view partly in section of the starting and braking means for the convertible lifting surfaces;

Fig. 11 illustrates diagrammatically the modiany suitable or conventional landing gear as, for

example, the landing gear halves 4 and a forward landing gear unit 5. These landing gears may be embodied in any suitable or conventional retracting means for retracting and housing the same in the fuselage I and for distending the same to the operative position for landing. A conventionallyarranged empennage is illustrated comprising a horizontal stabilizer 6; an elevator I, a vertical fin 8, and a rudder 9. A tail skid I0 is also provided and a traction propeller II is illustrated which is driven by a power plant I2 schematically shown.

. As above stated the craft is convertible for operation either as a gliding type of craft, a helicopter or an auto-rotative gyro. When operating as a glider the upper and lower wings 2 and 3 are fixed against rotation. When operating as a rotar wing craft the wings 2 and 3 rotate in opposite directions with all the advantages incident thereto when operating either as a helicopter or as a gyro.

Fig. 4 illustrates somewhat diagrammatically the mounting of the wings 2 and 3 and the drive for rotation and the transmission, it being understood the drive and transmission are for illustrative purposes only and that other drives and transmissions may be used. The upper wing 2 is mounted on the upper end of the central hollow shaft l5 which is journaled in bearingsJB disposed at the lower end of bearings H which in the particular embodiment shown are disposed between the upper and lower surface of the wing 3. The wing 3 is mounted on the upper end of a hollow shaft I8 of larger diameter than the shaft I5 and surrounding the latter and in the par ticular embodiment shown a bearing I1 is disposed between the upper end of the shaft I8 and the shaft I5. The shaft I8 is journaled in a set of lower bearings I9,and an upper set of bearings 20, these bearings I9 and 20 being carried by parts of the aircraft frame indicated at 2I and 22, respectively. The part of the frame for retaining the bearing I6 is designated I6.

The drive for rotating the shafts I5 and I8 carrying the wings 2 and 3 comprises a main drive shaft 25 suitably journaled and mounted on some fixed part of the craft, as for example the fuselage I and driven by the main power plant I2. This shaft is for driving the wings 2 and 3 when operating as a helicopter. A transmission between the shaft 25 on the one hand and the vertical shafts I5 and I8 on the other, is illustrated as comprising a shaft 26 which is also suitably journaled and mounted in the fuselage I and carries a gear 21 which meshes with a gear 28 keyed to a sleeve 29 surrounding the shaft and capable of being coupled thereto, as hereinafter described. There is also keyed to the shaft 26 a bevel gear 30 meshing with the bevel gear 3| keyed to the vertical shaft I8 for rotating the lower'wing 3. The shaft 25 also carries a bevel gear 32 which meshes with the bevel gear 33 which is keyed to the vertical shaft I5 for rotating the upper wing 2.

The sleeve 29 which surrounds shaft 25 is journaled upon the shaft 25 by means of the bearings 34 and 35 and carries a clutch element 36 which cooperatively functions with another clutch element 31 which is keyed to the shaft 25 (Fig. 9). The clutch element 31 is keyed to the shaft 25 by means of a key 38 sliding in a slot on the shaft 25 and means are shown at 39 for actuating the clutch element 31 to couple and uncouple the shaft 25 with the drive shaft 26.

The shaft 26 also carries on its righthand end (Fig. 4) a spur gear 40 which meshes with another spur gear 4I keyed to the shaft 43 of a starting motor 44. The motor 44 is utilized for starting the rotation ofthe wings 2 and 3 from rest upon conversion from fixed wing to rotary wing operation and for that purpose it may be of any suitable type of motor, as for example, electric, hydraulic or air. By this means the wings 2 and 3 may be started to auto rotative speed even if the main power plant fails.

The upper wing 2 is provided with wing halves 50 which are adjustable about a transverse axis shown in dot-and-dash line 5| (Fig. 2) and in the particular embodiment shown the wing 2 is provided with a central section 53 which is not adjustable. The lower wing 3 is provided with wing halves 54 and 55 which are adjustable about transverse axes shown in dash lines 54 and 55' respectively. In the case of the lower wing the axes 54' and 55' are not located centrally of the wing cord but are located forwardly of the center line of the wing halves with reference to the clockwise rotation of the lower wing looking at Fig. 2.

One or both wings .2 and 3 may be provided with means for applying to the wing halves equal adjustments about their axes of adjustment for equal vertical lift control, differential or unequal adjustments, and periodic adjustments. By periodic adjustments is meant the application of certain angles of incidence to the wing halves at points in the rotation. In the particular embodiment of the invention illustrated the upper wing 2 is provided only with equal adjustments is understood that when the correspondingly numbered parts (93'and 95) are actuated by the mechanism-shown in Figs. 7, 8 and 8a that the desired tiltin movements of the ring 16 about the transverse axes are obtained.

' :Thus when the craft is operating as a rotating wing craft the pilot has complete control of the rotors through manipulation of the control rods 03, SI, 93 and 95. When operating as a helicopter the vertical lift controls of the wings 2 and 3 may be efiected by the manipulation of the rods 63 and BI, while the operation of the periodic controls of the wing 3 may be eifected by manipulating the control members 93 and 95; When operating as a gyro thevertical lift controls of the rotating wing 3 are neutralized, and the'vertical lift controls of the rotating wing 2tmay also be utilized while the craft is operating as a rotating wing craft, although more efficient operation may be obtained by utilizing the vertical lift controls of the rotating wing 2 for obtaining increased lift of the combined rotating wing system.

The vertical lift controls of either or both of the rotating wings 2 and 3 may be employed for lateral control when the craft is operating as a fixed wing craft, as will be more particularly hereinafter set forth. Likewise the rotor controls or certain of them may be utilized for the other controls during fixed wing operation such, for example, as longitudinal control as will hereinafter appear.

The rotating win'g system 2 and 3 may be oriented and locked for fixed plane operation in any suitable manner. A schematic means is shown in-Figs. 4a and 51) for holding and locking the rotating wings 2 and 3 transversely of the fuselage for fixed wing operation. In the particular embodiment shown in Fig. 4, this means comprises a hub I keyed to the shaft I8 and a lock means IOI which cooperatively functions with the hub I00 to lock and hold the shaft I8 and thereby the rotating wing system in fixed position properly oriented for fixed wing operation. The hub I00 is formed on its periphery with a double spiral I03 and I04 terminated at their deepest points by the shoulders I03 and I04. This lock means comprises a pivoted member 105 which is pivotally anchored to the frame of the craft at I06. One end of this locking member I05 is provided with a locking end surface I 05 which engages the shoulder I04 of the spiral I04 in the locked position. This lock means comprises also a cooperating locking member I01 which i mounted on a pivot I08 fixedly carried by the frame, and the member I01 is provided with a slot I09 extending generally longitudinally of the locking member I01 to provide for relative longitudinal movement of the member and the pin I08. The member I01 overlaps the member I05 and is operatively connected therewith through a pin H0 fixed to the member I05 and a transverse slot III formed in the member I01 in which the pin H0 functions. The end of the member I01 adjacent the slot III is biased in a clockwise direction by spring I I2 fastened at one end to the frame of the craft and at the other end to the member I01. This spring tends to cause the lefthand end of the slot II I (Fig. 5a) to engage the pin IIO. Fig. 5a shows the members I05 and I01 in locking position engaging with their end surfaces I05 and I01 functioning as locking lugs to engage respectively the shoulders I04 and I03. In this position the rotor wings 2 and 3 are oriented and locked firmly in position-for operating as fixed wings. Fig. 5b shows the position of the locking members I05 and I01 out of lockin position with the rotor wings 2 and 3 rotating- As hereinafter more particularly described,--the rotor wings 2 and 3 may be arrested'in rotation. When so arrested therotorwingsZ and 3 are oriented and locked by the means shownin Figs. 4, 5a and 5b. While the craft is operating as a rotary wing craft the members I05 and I01 are held out of locking engagement, as shown in Fig. 5b, by a control mem-- ber I25 sliding in a guide I26 and having an operating end I21. The latter engages the end of the locking member I05 to rotate it clockwise about the pivot lflt, thereby lifting the locking member I05 out of the path of the shoulder I04. In the particula embodiment shown, the end I28 of the member I05 is indicated as having a surface which is roughly at right angles to the releasing memberIZE. When the member I25 is actuated to move towards the surface I28 and engage and operate the same, the end I05 of the member I05 is lifted from engagement with the locking shoulder I04 and through the pin slot operatedconnection IIOI II the lever I01 is operated counterclockwise about the pin I08 to lift the end I01 out of engagement with the shoulder I03, thereby completely releasing the hub I00 and thereby the shaft I8, transmission, and the shaft I5 for rotation.

When it is desired to arrest the rotation of the wings 2 and 3 for fixed plane operation, the operatin member I25 ismoved through the guide I26 from engagement with the operating surface I28 of the member I05, thereby freeing the member I05 for later orienting and locking operation. The end I05 of the member I05 is retained in the position shown inFig. 51) out of alinement with'the shoulder I04 by means of the member I01 through the pin slot connection I I0-I I I, the member I01 being prevented from moving longitudinally of the slot I00 by the frictional engagement of the member I01 against the periphery of the hub I00. This frictional holding operation is also assisted by the spring III! which pulls at an angle less than a right angle with one end of the member I01 thereby tending to hold the lefthand end of the slot I09 against the fixed pin I00. The shaft I3 and the hub I00 may be braked in any suitable manner to arrest the rotation. Upon the complete stoppage of the shaft I8 andthe rotors a rotating means, hereinafter described, reverses the rotation of the system until the shoulder I03, engages the end I01 of the member I01, and the member I01 is thereby actuated through the length of the slot I09 to operate the member I05 counterclockwise about its pivotal connection I06 to cause the end I05 to move down into locking engagement with the shoulder I04. I

When an electric motor 44 is utilized for starting the rotating system to rotate from fixed wing operation, the same motor may be utilized for reversing the rotating force applied to the rotating system when the system comes to complete rest to effect the orienting and operating of the wings above described. Any suitable means may be providedfor controlling the motor 44 in the starting, braking and reversing operations. These control. means being conventional, the details thereof are omittedfor convenience in illustration. This control means is schematically illustrated as being contained in a control unit I30 (Fig. 4). A primary control member I3I, which reciprocates horizontally (Fig- 4), when operv eohtrol eentaihed ixi togated to the right froih-thempositienshown, en-

T gages a starting switch member 8 32 W mea s of a lug l 33 carried by the =rlr'1em her for connecting the-motor 44 in ci'r euit for' starting the rotating wingsysteinl from fixed-plane position.

The motor 4 1 is r'quired only to 'brin the speed of the rotor wing s "2 and 3 to a point where the auto rotatientakes over and speeds the; Wings {2 as'a g'yre-er asa heli'eopter. When it is desired to teeters tdfiiid' plane op'erzaitiozi} thetr'otdr wings a tion of the valveul fii. If-the ai is conningv in from M9111 the valve, this valvewill he in dotted line :positien, and if the a in is coming h'em thechambe'r I50,wthisva1ve-i vill be in the full line position illustrated inFig 1 0. The chamv ber lfifl is connected with a "chamber; i5 2 Lhy means of a; poppet valvei53, and the latte is provided; W-i th -a' stem I53 having a :link con- 7 tneetion H34 with one arm oi-a bel l ci'ahk 1 55 Yihust be braked and lbfeugh't down t6: 'z'ere' speed.

" bfaki ng be accomplished Joy any arrahgem er'it'fof fsuitable braking means arid the meter 'fif'may'i be centieiftd' to a] generator sulpload circuit for assisting in we the le'f an this nievenieht auses a' lug J34 "pivetally fastened to the frame structure at let. The other'encliofthe longer arm of the hell crank its, is pivetally fastened "at 1 st n t9 the ;t'rm l 5a of the bellerar ik pivoted at we to the; frame whereby 'iipon operation-of the hell crank aim i58'thebel1 (team: is actuated to openor clese the pobidet valve 153; The passage I41 of the r'fietoi is eennected with" ch mbe'leeg The ehainbei [6'0 leads out to the atrhfcspheie' thrd igh a pipe it! in which is a flap Va-Welt?! hating an Operatingerm 182', the lattenbeing 'cognected bya lihk'fifit iwith one end ofalever ISB -pit ot'a'llymoiinted'at one end of the levjei ea a rh'eans contain T30 ednneets the 'n'io'tei a (Syn D load "eir'ciiit. lien reter wing system? rid 3 poines to Testfan ai'itomatic' means'ic0htai1'ied in the 'contfehbex I utilizedlto diseonneet the Thin 'dQtQ reconnect the t V r u1t'"f r;reverse op- "c 'c'uitf [35 Whichleads through :5. byjthe locking and orient- This'f'StfitCh "13B ihomprises a VCOY stemm hyafsprihg' 'an ltl and a conta'iet 13:8 carried by the farni 105', arid whenj the 2:5 is nga e the '{ontioi me ber z's stem for "j qtation, this he' switch I36, but the "i n' mbe j H15 F ce int m h'e shdulderfj qfi, that i eve se et'oi M is interrupted. e" e1 i ee n the 'staiqtlhg switch control member E32, I,

e; t we: A rwe d esteem so? as :to" Start; the rotating The'fltiidpressure jmetor l which "serve as the intakearid leg;- jhaiist passages fat. the miitor and: pump. "The V V 46 lGaHS EOa CHambEF ohtrel therefor are schematically t t is prov-ldedwith a pair-pi passages 470 recess has an appfoxiihately' radial surfa'ee positioh hqwn" (Fig.11d) this fluid pressure deyiee "is im lat d by, closirig'the pope ehg'aged with a locking men ihe1," through a 'pinlfil' isposes in the s otfiee; .Theldckihg memb r as? as reciitzifoeably" mcuflnted with the inner endadafited tofent'eit a meme recess I68 formedin One side (if the rater disk [43. IE9 exteric'iingjail the way d nto the depth o he recess ljfiafifojin the periphery of the mtor' ellsk M3, and On the jothelf sidea parallel surface 170 Qf substantially smaller depth than thesuifaee I69)" Between the upper edge df the'sti' z f aeef I10 and the peripheryfof the rotor" !43' is dispsed' a gradlial eurve surface Fit, the latter gratll'ially 'n ier'gin'g into the peiiphefyof the rotoiifdisk I43. "Bythis arrangement the irinerend Of the king' lug' or member i6? is; held against the retatinfg rotor M3 by'nieans of a pairef springs I12, and the locking: lug lST inste'ad of dr'epiiiii to the l'ower part of the loekingireeess I618, strikes the 'eiirved' surfaee 5 'i I The disc rotor I43 is pr otidedlon its peripheify eoin'modating a flange l42' which is fastened} in any suitable mazinerto thecasing M2" oh the in terior thefeof and this flangeforms a se'alihgrside wallforthe vanes M4 on oheside, whileone end of the casing informs a sealing edge on the ether "side. Thus referring to'Fig. 9 the upper part of the r otq'r diseeiet vforms the fluid pressure Dart of the i nitwhile the part of'the rotor l43be1ow the flange i 32 co taiiis the i ec'ess 563 Whieh c The fiuid' piessu're oleViee 141i functions either as amotqr tor as a p'lhhp or compressor. In the ugh the the dotted line position, and exhausts the air through chambers I41, I66, and thence through the pipe I14, I14 into the storage tank I46. In the portion I14 of this pipe is disposed a one-way or check valve I15 which permits a pressure of air to be forced into the pipe section I14 but prevents backfiow. The work done by the fluid pressure device MI in storing air under pressure in of the spring I 12, this locking plunger cannot fall into the locking recess I68 until the rotor comes to rest, since the plunger jumps the recess and falls upon the inclined or curved bearing surface 'I1I so long as the rotor has any appreciable speed. If the rotor should stop with the locking plunger I61 alined with the bottom of the recess I68, then the springs I12 would urge the plunger to the bottom of the recess, thereby locking the rotor I43 and the wing system. In this position the rotor wings are properly oriented for fixed wing operation. If the rotor comes to rest at a 'difierent position relatively to the plunger I61,

then the fluid presure device I 4| operates as .a motor in reverse, and this reverse operation, in-

locking plunger resting on the periphery of the rotor I43 until the inner end of the plunger I63 runs down the curved surface Ill and slips into "the locking recess I68. The reverse operation of the fluid pressure device I4! is efiected as follows. The pipe section I14 leads into a chamber I16,

which chamber may be put in communication with chamber I60 through a poppet valve I11. The latter valve has a stem I11 which is guided through the walls of the chamber I16 in its opening and closing movements, and this stem is provided with a pin or lug I18 which is disposed in the path of the lever arm I64, whereby when the lever I64 is operated about the pivot I65 in a clockwise direction the poppet valve I11is closed thereby. The valve stem I11 is pivotallyfasten'ed at its outer end at I19 to a pair of toggles I80; the other ends of these toggles I60 being provided with longitudinal slots I86 which accommodate fixed pins I8 I carried by a pair of frame members I82 which are fastened to the walls of the chamber I16. The toggles I60 are biased by the toggle spring I83 in such a manner as to holdthe valve I11 in its actuated position. As the rotor I43 creases,and when that pressure falls s'ufiiciently below the pressure in the tank I40 the difierence inpressure above and below the valve I11 operates the valve in an inward directio'ntof open the j same against the tension of the togglespring I83,

causing the toggles to collapse with the spring I83 foccupying the position on the other-side of the pivotal point I19. The valve I62 having been closed when theg bell crank I58 is moved to the position for converting to fixed win operation from rotary wing, the fluid pressure device i now lconnected up for reverse operation, with the pressure'of the tank I40 being supplied through the dicated by the dotted arrow, continues with the slows up during the brakin operation, thepressure in the chambers I41 and I60 gradually de- "55 pipe I14 to the chamber I16 and thence to the chambers I41 to operate to exert a force tending to rotate the rotor I43 counterclockwise (Fig. 10)

After the opening of the valve I11 the brakin operation. is continued until a complete stop occurs, whereupon the reverse operation, as above indicated, takes place for a partial rotation of the two arms or links.

the rotor 43 to bring the plunger I61 into the locking and orienting recess I68. When this happens the springs I12 actuate the lever I64 about the pivot I65 clockwise through the pin slot connection I61, I66 to engage the pin I16 of the valve stem and reclose the valve.

As indicated, the flap valve I62 is operated by the arm I62 fastened to it and the arm I62 is pivotally connected to a link I63 at one end with the other end pivotally connected with the lever I64. The pipe I6I is provided with an enlarged chamber I6I for accommodating the flap valve I62 and this flap or wing valve remains closed'during that part of the stroke of the locking member I61 between the periphery of the rotor I43 and the bottom of the recess I68, and the valve is opened and closed by that part of the movement of the member I61 between the point where it rests on the rotor I43 and the point where it is actuated by the bell crank I58 to its outermost position. The valve I11 is open 'only during the last portion of the arresting or alining operation, and the closure thereof retains the pressure remaining in tank I40 to be used in starting rotation of the wings when converting to rotary operation.

The bell crank I58 may be operated about the pivot I50 in any suitable manner, as for example by having the other arm of the bell crank lever operatively connected to a control link 425. The bell crank lever I58 and the link 425 occupy two positions; one position which is shown in full lines (Figs. 9 and 10) being the position just after initiating the starting operation for conversion from fixed wing to rotary wing. The other bell crank position is indicated in dotted line position (Fig. 9) which corresponds to the braking position of the fluid pressure device I4I for slowing the rotary wings down andarresting their rotation. The arm I58, moving from the dotted line position to the full line position (Fig. 9), engages a lug I86 formed on the plunger I61 to withdraw the plunger I61 from the locking recess I68.

I The link 425 is operated by a link or arm I25 through a link pivoted at 3| 4 to a fixed part of the frame, this link having a pin slot connection with the arm I25 and the link 425 and functioning to reverse the direction of movements of The operating arm I25 for the bell crank I58 may be operated in any suitable manner but preferably by the unitary member and associated means hereinafter described in Fig. '1. Fig. 7 shows the hook-up ,for operating the arm I25 and I3I described above with respect to the modification of Figs. 4, 5A and 5B and it is understood that when the embodiment of the starting, braking and locking .means of Figs. 9 and 10 is employed, the arm I25 is operatively connected with the member 85 similarly to the connections of the arm I25 'to the member 85. p The fluid pressure starting and braking device MI is illustrated in the embodiment of Fig. 9. In this embodiment the rotor-rings 2 and 3' are of the same length and 'are operated at the same speed. The spur gear I60 is carried by a stub shaft I9I, this stub shaft beingmounted in bearings in any suitable manner. One end of the stub shaft I9I carries a beveled gear I92 which meshes with larger beveled gears I93 and I94, the former being coupled to the shaft I5, as by being keyed thereto, and the latter, namely I94, being keyed to the shaft I8, the gears I93 and I94 being of the theyoke member 236 is a pin 233 carried by the bell crank and located in an open ended slot formed in an upwardly projecting ear 200 from the yoke member 236. The operating connection 9| for the vertical control of the lower wing 3 is similarly connected with one side of the bifurcated yoke member 236 through a bell crank 2M pivoted for movements about the pin 234 carried by the block 23l, the bell crank 2M having a universal connection with the arm 242 extending upwardly and coupled with the connection 9!. The other arm of the bell crank 24! is'connected with one of the bifurcated members of ,the yoke, 236 similarly to the connection of ,the bell crank 233. The link 242 is pivotally fastened to a bracket 243 swiveled to a slide 244 moving, in a fixed guideway 285 extending generally .parallel with the link 242.

Thus by rotating the manual control l, 202 through the wheel 202' the lefthand end of the lever 225 may be moved up and down to operate the vertical lift controls 10 and 9! which changes the angles of the wing halves of either rotor in equal amounts for helicopter operation. The angles for vertical lift assumed by one of the rotor wings may be equal to those of the other rotor but in the particular embodiment of Fig. 1 wherein the lower rotor wing 3 operates at a greater speed than that of the upper rotor wing 2, I have indicated the vertical lift angles for the upper wing as being somewhat greater than the angles for vertical lift of the lower wing 3. In the case of the embodiment of Fig. 9 where the upper and lower rotor wings are of the same span and operate at the same speed, it may be desirable to have the angles for vertical lift of the lower rotor wing somewhat greater than the angles of the upper wing due to the interference with the efliciency of the lower wing. These vertical lift controls are effected solely by the up and down manipulation of the lever 225 about its pivot 226.

,It may be desirable to vary the vertical lift controlsof the two wings reversely with respect to each other, that is decreasing the vertical lift angles of one rotor while increasing the angles of the other. Thus for any setting of the lever 225 in vertical planes about the pivot 226, the pilot may effect this differential control through the manual operating lever 238, for example, by utilizing this lever as a foot pedal, that is by reciprocating the yoke 236 to the right and left (Fig. 8). The bell cranks 233 and 2 are operated reversely about the pivot 234 to difi erentially vary the lift angles of either wing with respect to the other, namely the lift angle of either ofthe wings may be decreased while the liftiangle of the other wing is increased. The bell crank arms 233 and 2 are provided with extensions 246 which are yieldingly biased to a the rudder and differentially varying the lift angles of the two rotors. The rudder 9 is connected with the pedal238' by means of a rod 248. The periodic controls which in the embodiment herein shown are only included in the lower rotor wing, are operated by the swinging movements of the manual member 202 about the universal joint 203. For example, by swinging the manual member 202 longitudinally of the lever 225 the periodic control member 93 for the lower wing 3 is operated- This is effected through a bell crank, one arm 250 of which is universally connected with the lever 225 at its free end and pivotally connected with a bracket 25l swiveled to a slide 252 guided in a guideway 253 of the fixed member. The other arm 250' of the bell crank is operatively connected with the link 93 which operates that periodic control.

The other periodic control which is operated through the link connection.95 is effected when the manual member 202 is swung about the universal 203 in a plane vertical to the paper with the bracket 22! swiveling about the slide 228. This operating connection includes a bell crank, one arm 255 of which has a universal connection with the lever 225 with the bell crank being pivoted at 256 to a bracket swiveled in a slide 25'! movable in a fixed guideway 258 disposed substantially at right angles to the lever 225, thus these particular swinging movements of the lever 225 result in the right-angular part 225 of the lever moving in the direction of its length. The other arm of the bell crank lever is operatively connected with the connecting link 95 for effecting the other periodic, control.

Combinations of these various controls may be effected simultaneously by the manipulation of the manual member 202. For example, by swinging the member 202 about the universal 203 to impart components of movement to lever 225 lengthwise thereof and at angles thereto, both the periodic controls, links 93 and 95 are simultaneously proportionately effected, and by simultaneously turning the wheel 202 to impart com ponents of movement to the lever 225 in vertical planes, the lift controls of the two rotor wings may be simultaneously effected.

.When the vertical lift controls 10 and 9| are operated by the control member 225 to vary the vertical lift controls of the upper and lower wings the periodic control members 93 and 95 are simultaneously lifted or lowered by the control member 225 and proportionately to the operation of the control member 9|, so that the setting of the controls 93 and 95 is not effected by the mere up-and-down movement of the control member 225. Thus the operation of the control member 9! for varying the vertical control of the lower wing does not appreciably change the setting of the periodic controls although of course as pointed out above either or both of the periodic controls effected by the members 93 and 95 may be simultaneously changed by the corresponding movement or movements of the control member 225" to bring this about. Thus the ring control unit of Figs. 5 and 6 is lifted as aunit to vary the vertical lift of the lower wing without either interfering with the previous periodic control settings or with their independent simultaneous operation. This operation is clear from Figs. 7, 8 and 8A which show that the up-and-down movements of the control member 225 merely operate the bell crank units 250 and 255 to lift or lowerlongitudinally the control members 93 and 95 respectively, the slides 252 and 251 merely moving in the respective fixed guide paths 253 and 258. The bracket 25l to guide paths so as notto interfere with the movements of the control member 225' necessary to seasons 19 for fixed plane control; or controlfin fixed win operation, namely I have provided'for-the utilization of the vertical liftcontrol of thelower wing for both vertical lift controlduring "helicopter flight and for lateral control during fixed wing type of operation, and theperiodiccontrols are utilized as describedabove for gyro operation and also for elevational controlfor fixed'wingtype of operation thereby simplifying-thecontrol mechanismocf the craft. 2 Figs. 1A and 1B show schematically the adjustments of the lower wing 3,--3' for assisting in the elevational control and for obtainingiateral control respectively. p The elevational control for fixed wing operation is effected through the manipulation of the connection 95 leading to one of the periodic controls of the lower wing. That is, when the manual member 202 isswung in planesatrig'ht angles to the lever 225 this-adjusts the wing halves-of the lower wing in the same direction" as shownin Fig. 1A to assist the elevational control effected by the rod 212 through similar movements of the -manual member 202. This is effected through the operation of the control 95which "tilts the control rings about the axis 81, 81 thereby depressing the trailing edge .of onewing half and raising the leading edge of the other wing half, effecting movement of both wing halves in-the same direction. 1

The lateral control for fixed wing'operati'on, which is wholly eflected through the differential adjustments of 'the wing-halves of the lower wing, -is effected through the manipulation of the operating connection 9|. The swinging movement of the manual member 202 in the plane of} the drawing effects this operation. The operativeconnection between" the manual member 202 and the connection 9| includes-a bracket 28l fixedto the operating rod 242, a link 282 having universal connections at one end with the bracket 281 and at'the other end-with a-bell crank lever 283 which is-pivotally fastened at '204 to an extension 243" of the bracket 243 which 1 is swivelled to theslide 24 i. The other arm 283' -of the bell crank lever has a universal connection with the part 225; of the lever 225, so that when the lever 225 is moved to the right and left in Fig. 7 the bell crank 283, 283 is operated to operate the connection 9i and thereby the wing halves of the lower Wing'to effect the-lateral con- 'trol of the craft for fixed wing operation. The slide 244 is guided in an elongated guide -'for sliding movements relativelyto the guide 205 in one direction, and the guide 205is carried by a supporting member 286 which is slidable in'a guide 28! in a direction at right angles 'to the guide 285. A lever 288 pivoted at' 289' to a' fixed part of the frame has a locking lug 285 which passes down through an opening of'thegui'd 281 to lock the member 206 against slidingmovement in the guide 281. The other end--of =the lever 288v is provided with a slot 2-90 which accommodates a pin 29! onthe rod or shaft'85.

for operation by the shaft or rod 85. When-the locking lever 288 is out of :engagement withthe member 286, 286 the operation of the bell crank 283, 283 does not effect operation of the rodpr link 242 because the pivot 284 is'not fixed, due'to Y the sliding of the slide member 285. This is shown more in detail in Fig. 7B-. During fixed wing operation the yoke 236 remains-outof operative engagement with the bell cranks 233: and -24I, and the Wing halves of the upper win g are .fixed against adjustment; The operative' connection 93 is dperatd "during fixed wing operation, but such. manipulation merely means the tilting ofthe ring about theaxes of the operative connections -19 of the wing half so-that no adjustment takes place; t.

The conversion from gyro operation to fixed wing'opcration includes the above described control of the starting motors to act as a brake for slowingup or expediting the slowing up and M arrest of the wing with the-wings being brought to rest, oriented and locked in the orienting positi'on for fixed wing operation. With the wings locked and oriented in position, the pilot sets his throttle by manipulating the handle 21 l to obtain the required traction and, if deemed advisable,

he may also adjust 'the pitch control of th propeller l I ,any conventional manual adjustment of said pitch being employed and omitted from the drawing :for convenience in illustration. o I The conversions in the reverse direction, namely, from fixed wing' operation to gyro and then toghelicopter, are obvious from the above description, and either or all of these conversiohs may be safely made while the craft is in flight. i

Another importantfeature of the invention is the provision of a single conversion control means, namely, a shaft'or rod 85, by the manipulation of which: the conversion controls are ini- -;3 tiated and operated in the-order desired to effect quick and'isafeconversions. This rod 05 is reciproceited by a lever L-pivotally mounted at 300 toa'fixed part of the frame. This lever on one'endis provided with an elongated slot 3M which engagesa pin-302 on the rod 85 and moves it through an angle indicated in Fig. 7 between the full'line position and the broken line. With the lever L in the full line position the plane is operating as a helicopter. When it is desired to :10 convert from helicopter to a gyro, the lever L is moved' downward to the position indicated in dottedlinesnam'ely, through an angle approxirnately one-half-the whole range. This operation moves the rod 85/upwardly which operates 54 the lever 219, the link 218, the shaft 2| 1, the bell crank 2M and the link 2Il to actuate the toggles -fromthe full line position to the dotted line position; whereby'the adjusting nut 205 is swung upwardly to release the manual member 201, 202,

415 pe'rmittingthe latter to drop by gravity with the collar 22! resting upon the limiting stop 222. If 'it does notdrop by gravity the bell crank 2M engages the collar 22! and forces it downwardly. Thisdownward movement also; I as described (.5 above, operates the bell crank 26l to adjust the throttle of the engine to-the desired power output of the'engine corresponding to gyro operation. Thisinovement of the rod 85 also operates theconnection' 39 to disengage the power clutch .5 0 st, 3? and simultaneously to change the pitch of the propeller l-l for the desired traction while operating as agyro. This operation of the conne'ction 39 is connected through a bell crank 303 'pivotally fixed to the frame at 304 and having a pivotal connectionwith the connection 39 at 305. "The other arm of'the bell crank lever 303 has a pivotal driving connectionwith the rod 85 through a pin- 300 carried by the latter. This i driving connection is only operative during the "7!) first-half of themovement of the lever L which -results in the actuationof the 'bellcrank 303 to -='-th;e dash line position. In that position the pin 306 is disposed'in a slot 301 formed in an arm disposed at right angles to the arr'n of the bell -crank.- The movement of the shaft also acit the operation loathe new;eotioasMo t veriticaliliitqcontrol ot shew lower xwing;.iis xals'o men-J- tralizedufexcept iZfOlif any: adjustment due to :the

operation: oiheithenr ot thewperiodic controls a". lnzconvertingw :tromwgyrm :sperationf; fitted wing operationtheilevesm isamoved down" to dashk positiom shown the i corresponding completiomof aha-upward: movement on th'eshaiit latterz'mwementiof the snaftmsaoper atestheleveriiarto theldashpositionanidzpushes theixshaift i 212?! @tnrthenitoithe leit; therebyi operaatiiig the openatingi ilever: 2 l4:% ationtsthe he'll crank lever H3 and the link ZM JJbWUWQmmEIBIY retains theftogglea armsi imntlre; position showman stash-illness; This-further movement-m1. thetshait 12 iilroperates .tli'etbell;cranlttilacthrough thewpin eslotrdrive lflta-llimztcrflower zthe stopnolzlarfljtttoa heiiias'h positionsshownfortixed aha-Martha ia'oamttatam-last.was. operates the; lever-vim Th? the position shown in dash dines :to ':l'ook;. the: islidei member 7-2 86* against 'movement;:.therehy spermitting operation of ithe connection .19 t a to: iadfiustzdifferentially; 'thetmm halves pf the" dowel-.1 Willgfifbl iateraln'conitr'oli rfor twingroperati'om assxlescribedliabove 1 This latter of; the: movement-1o the: iewer aisoroperates: the wpera tinghconneetioni is to releasethemeaiiszheldingrthe ldckroutmf engage.

ment witha the: shaft: i8; -:,namely;: reteasingathe lever Hi gcfaFig; fal ldi' fiiBinzthei embodn merit shnwnvthereim or l'thewholdinnnlevervifidiiin theembodiment def ytioni otithecconnectionntfi isgeiieoted; through-a bell crank 3H1 pivotally fastened to a otgthe irametdt-iwith-mne armor: thei-belli-cramk being: pivotally *fastened; :tof ,the "connection; 425 and the otherrarm of the bell crank having operative-i :connectionmith a pin 3 i2, carriedrby the-shaftfiS: This-particular arm of the bell erankitrl Iris provided vwith an arm 313 disposed substantially at right angles thereto andwhaving a islotrlongitudinally of the arm 3133410 vprevent movementpt the bell crank -during the movement ofrthe' shaft: =85 for 1 conversion-from helicopter to gyro? .l .l I v The movementof the shaft-85 for conversion to; fixedlplane operation also operatesrtheaeontrol member-:1 31 ts engage the control fingeri35; for changing the -;connections; of, the motor-alto realise the latterjto function as abrakavas described:ahove-toaslowingqdbwn the rotating SySv i.'(Fi:g .F 4 is Thisis shown as iroperatedzirom the nperatin connection. I hich is.; fastened to-qthewcontrol'dt -(Fig; '1). illnwthe rcasejofathe embodiment), so stand; it) fithe operatinggl'ever l3l would be o tted-r: The latter; half, of 'the movement ottlae, shaft 85 in converting a to fixed 'wing operationgalso results zainwthe- {operation of the; lever-rim? ,t QIQQkTtih-B "slideflfi so as; tmprov-ide imam sf (301 113101; manna "operation, net scribed above With-either the embodiment; (of

theuelectricumotor; starter:and brake ofli igwi' r' or orienting and lockingkumembersa antoinatibahy wing operationxthe'full line positionoftheklimit Eing stop 222 shownin Fig 7 determines the yro setting angle of incidence for the wmg ha'lvesz Thisarrangement is used: whenitris desired that the gyrosett-ing of the wing halves shall be did:

ferentiromtthe airplane setting. "oflth'e :wing halves Thatis, the dash. line. position ni -the limiting stop-K222 determinesthe position of the vertical eontroLm'eans for fixed plane operation. By these. two: different positions- :of the: limiting step 222; one for. gyro andv the r otherx l-for fixed plane operation, I am enabledAtolpredetermi-ne the best vsettings tor each type of. operation. i

For safety in: conversion it is preferable-that thedever' L bezincapablesof occupying fian'yisot'her than one of the three positions corresponding to fixed plane, gyro and helicopter operations respectively; namely that the movements; ofi lever L may be arranged such that it moved. foristarta .ing a. ,phase; of conversion: and released; it will continuetocomplete the movement .ior thatspam- 'ticular conversion, for example; from-uplanewto gyro. When once started in itsfappropriate innovaconversion: completed, as in this :ca-s ito gyro andiurthervwhenonce started in the movement from; gyro to helicopter it will automatically com,- plete this movement. Furthermore,- 'in.vthe reirerseconversionlthe same action may ,eberarrangedhfor; the object being to make the operation ofillever- .Li imoreafool-prooil Any-suitable means may be provided for this purpose; .and:.-is omitted :for conveniencein illustrations:

the-embodiment oLFigsi 11 to 113, Lhane vshow-n val-modification of the controls: showman Figs; '7 'andq8 iwhereby theioot control natedtand all. of. the controlslembodiedzinvazsingle manual control n The manual memberflfilisstill rotated about its axis by means of a wheel 202! for adjusting-1; theovertical liftx contnols, we'xcept thatisieneithe wheel202"; is mounted on a counter "shaft 5315s 7 shaftv 3 t5 has; an torque; trans.-

- mittinz universal connectiona3ilfi -withvapvrorm gearri H; which; isq-enmeshed with, another. worm gear 31l;-8:'=which keyedate; the manual member 202. Thawormfil'l is,. iournaled in: a-brapket-MFQ carried ,abya rool lar sac surrounding the-manna! member 2M andliournaledrtherein; ,f-o lfl t i rotation-but fixed-i;.-ag-a-inst rel-ativze g lon ituclinal movements. Thea-shaft 31-5 v is, tsupportedi impart by the universal-joint 3+6, and theubracket are, and in part by al collar 320, "321i surrounding the member;ifllandwarrying:1a fright angleyarmiflm through -one;arm Gfz'IWhiCh the shaft Iii-5111s four.- naled. The collar 32| in turn'isi'snpportedsbyarods 323'":-"extending upwardly and fastened.- at" their uppers-ends to: a coli-ar -3 2-4 ijournaledzpaboutmathe vmarmal member 2412 25011 rotation thereaboutkbuii fixed jag-ainst relative iongitudinar movement. The acollar $24 is connected-phone side with operating link X23 1. rim; opera-ting lt-he bifurcated wokeafli; this acclimation ribetweenz-tl'ie 233.1 Y

2e. and the collar- 324 being by means ofail-ug- 324.; This. connection .is a universal connection. ..-On the opposite side ofathe collar is-disposeda similarilug 324' which is universally connected with the link 248 for operating the 'rudder;-;Thus.by rotating the wheel 202, theimanual member. -20l, 202 is rotated for adjustment .of thewertical lift controls. For rudder control and operationzof the connections 10 and 9] through the yoke 23.6., the wheel mount unit, including the ,shaft13l5; the arm 322, the collar 32l and the co1lar ;324 may be :rotated through-the requiredangle about the :universal joint 3l6.in either. direction, there- -by eliminating the necessity. for the .fo0t;control showninFig. 8. 1' Fig. 3A I .have illustrated a .newandsimproved landinggear comprising awheelliill and an axle 43! with the wheel 430 in its-,ground-engaging position inclined to the vertical. The tires are indicated at 432 and the wheelsare. provided .with rims 433 which are fastened to the periphe 'eries of the wheels in planes which are oifsetfrom theiplane-ofthe wheels byangles a equal :to the inclination of the wheels to the vertical plane indicated by the dot and dash line 434; By means of thisxconstruction the tires which otherwise :wouldtend .to be forced out of the rims, will.be retained therein against the load.

-I. claim:

In an aircraft, a convertible lifting surface with said .multiple means and'coordinating the converting operations. i 1

2. In an aircraft, a convertible lifting surface operable eitheras a fixed-surface or arrotatin'g esurface, multiple means for convertingv said surface from a rotating to a fixed-surface comprising 1- means for arresting the rotation of the surface, means for orienting the surface for fixedioperation and locking the surface in its fixeduoriented position and a single control element. whichiis operatively associated with saidtmultiplei' con:- verting means and determines the times of-their operation. ..-:-.w. I 3.. In an aircraft, an airfoil lifting surface mounted foroperation eithersuas afixeds-surface wing, a gyro or as a helicopter, said airfoil'sure face having portions variable inangles of; incidence, means forvarying theangles of incidence equally, -means for-varying the angles -of inc-idence periodically, a transmission including a clutch for transmitting rotary power to said air-'- foil surface, means for locking said surface against rotary movements, and conver'sioncontrol means controlling said several means and-movable in one direction to convert the craft from a='helicopter to agyro and then to a fixed airfoil craft, and movable in another direction to convert-the craft from a fixed airfoil plane to a gyro and then to a helicopter. l

4.- In an aircraft, a convertible lifting surface operable either as a fixed surface or a rotating f means for neutralizing said controls, multiple means for converting said surface from -'a rotatto 'a axed surface comprising"'mcalis 'fmf ar 75 resting the rotation of the surface, means for orienting the surface, and lockingthe surface in its fixedoriented. position for fixed operation and a single control element which is operatively associated with said controls and said multiple converting means for neutralizinglsaid controls and determining the times of operationfof said-multiple converting-means.

5. In an aircraft, an .airfoil lifting. surface mounted for operation .either as a' fixed surface, a gyro or a helicopter, said airfoil surface having portions variable in-angles of incidence, means for varying the angles of incidence equally, means for varying the angles of incidence periodically, means operatinglsaid portions for-fixed operation. controhmultiple means for convertingthe craft from a helicopter to'afixed surface operation and a single element operatively connected with said means and under the-control ofv the pilot for converting from helicopter to fixed surface operation which neutralizes the means for varying the angles of incidence equally, neu-. tralizes the means for varying the angles of incidence periodically; renders operative the fixed operation control means operating said portions and operating in the desired order the other conversion means.

6. In an aircraft, an airfoil lifting surface mounted'for operationeither as a fixed surface, a gyro or asa helicopter, said surfaces having portions variable in angles of incidence, means for varying the anglesi'ofincidence equally, means for varying the angles of incidence periodically, a transmission including a clutch for transmitting rotary power tosaid airfoil surfaces, means for arresting the rotation of said surfaces and orienting-and locking the same against rotary movementsl-in the oriented position, a traction propeller'and means for varying its pitch, a power plant and a throttle control and a single element under the control of the piloti controlling said several means andoperative in one direction to convert the craft from helicopter to gyro and then to fixed surface'operation which first neutralizes the means for varying the angles of incidence equally, increases the propeller pitch and decreases the throttle, and" then arrests, orients-and locks the rotating surfaces for fixed operation. I

'7. In an aircraft, a pair of convertible lifting surfaces operable eitheras-fixe'd surfaces or rotating surfaces'rotating in opposite directions, a control for each of saids'urfaces for controlling the lift, a control for'perioclically varying the angle of incidence of at least one of said surfaces while operating asa rotating surface craft, a traction propeller of variable pitch, a powerplant for driving said rotating surface and said propeller, means for varying the propeller pitch, a clutch for coupling the power plantto the rotating surfaces, :means for arresting, OrientingJandlOcking the surfaces for V fixed operation and converting" the craft from a helicopterto' fixed surface operation 'comprising'a single element under the control of the pilot which is operatively connected with said controls and converting means for first disengaging the rotating "surfacesfrom the power plant' and neutralizing the -vertical lift controls and then neutralizing the periodical incidence controls and arresting, orienting and locking the surfaces in the fixed wing position.

8.' In an aircraft, a pair of convertible lifting surfaces operable'either as a gyro or helicopter and rotating in opposite directions, each of said lifting-surfaces having portlons variablein an,

the other of saidsurfaceslooth edually K, J p

'odi'ca'lly', means for neutralizing the controls for traction propeller, a power pl Eglesofincidence meanstfor varying; theportions M;- one surfacewequally, 121531113"; for varyingathe version means for said scraft comprising means for controllingrthe olutc and 'the powei plarit and neutralizing oand nclering operative the controls for varying the portions of the surfaces equally upori conversion from-one type of rotary operation to the other 1;

9. In an aircraft, a pair of 'll iftin g surfaces operable .either ,as fixedsurfaces or as rotating surfaces, rotatin i'n"opposite directions, each of said surfaces' having portions vari able angles of incidence, mea {for varying the variable incidence portions 0 one of faces equally, means for yaryi varying portions of the surfaces equally upon COIIVBI'SiOHflOIII helicopterjgyro operation," a traction propeller; a; powerplant for driving, the traction propeller and-rotating said surfaces; and

, means for convertingsaid' craft from one; type of operation to the otherwhile the airf. j 1

0. In an aircraft, a 'pairfofi convertible lifting :.2

surfaces operable either as fi xedfsurface's"or'las iroltatin'g surfaces, rotatingirroppbsite directions,

each of said surfaces" having portions; variable angles of'in'cidence, means [for var 'ng the variable incidence portions of., one of saidsurfaces equally, means for varying the portions {of I the other of said surfaces both e uallyuand periodicall-y, means" for neutralizing the controls for varying portions of thesurfaces equallylipon conversion from helicoptert traction propeller and rotatingysaid surfacesand .means for converting "said craftfrom m ltose-of operation to the other while m1 the airncludin means for arresting th rotation, orienting and locking said rotating surfac'es foffixed operation.

1L. In an aircraft, aconvertible lifting surfa-cge opera le either a a riv amtat s sur ace or as an autorotative surface and control means for varying its angle of incidence to its plane of rotasurface and from operation as anauto-rotative surface to operation as a driven rotating surface. 12. In an aircraft, a convertible lifting surface operable either as a fixed wing surface or as a rotating wing surface and control means for varying its angle of incidence to its plane of rotation for controlling its lift, traction means, means for conversion from one type of operation to the other, and means responsive to the last-mentioned means for varying the aircraft traction pull when changing from ;a rotating surface to a fixed wing and from a fixed wing to a rotating surface.

13. In an aircraft, a convertiblelifting surface operable either as a fixed wing surface or as rotating surface, controls forrotary Wing operation including vertical lift control means, means for periodically varying the angle of incidence of said surface, directional control means, and cone.

gyro oper ion-aft ntrols; for fined *wingi operation, and asingle set of v 14; In an aircraft ai lifting surface mounted for: operation:- either as 1a.: :fixed surf-ace or as" a rotating surface; and -eiectrodynam icpower "meansifcr stazrting: said :liftingr surface from: rest forioperatiorr as a rotary "surfacexandi means asso ciated with the power meamsvfor operating as ar-aketoarrest the-rotationofasaidsli iting sur iiaee: uponqconyersion tofixed s-urfaceoperation, --together with means for orienting and locking :said surfacein theffixed operating positions a 1 5; ani aiircra'ftg a iif ting surface mounted for operation either as-=a fifxed'surf ace or as arovwaitingsurfer: e, and-"nuid-pressure power means --fo ristartingisaid jli i'ting surface from" rest for operation as a -rotary"-'surfa-ice andmeans'f'or "operating the powen as a brake to arrest the rotation of saicllifting'snrface upon oonver si'on "to fixed -"sui'face operation, together with nieans for orienting and -l-oolri-ng'sarid surf-ace in the fixed'operati ngi position; l

- "16'. In arr aircraft,--a lifting-- surface mounted for operation either as affixed surface or as a rotating surface, and power means for starting said lifting surface from rest for operation-are rotary surface and means associated'with the power means for operating it asza brake to arrest the-rotation or" said lifting surface upon conver gel 1 [tanked-"surface operation, together with rn eafns for-orientingand locking said surface'in the fixed {operating position, said" power means heing reversed after complete stoppage of the 17."In an aircraft, a convertiblel'ifting surface operable either, as av fixed wing 7 surface or as a rotating, surfaceyjcontrol mean cfor varying its angle of incidence; to its plane of rotationf'or ntrpllingits: lift, an outer race above the center o rotation of said surface and. a link fastening the, outer" race adjustably about i the circumfere ice of said race to obtain. thedesiredlead. from thepilotfs manipulation oflsaidrace'to, its effect fupon, the. -.s.tabil,ity -ofl the aircraft,

' l8; anhaircrafrofi hetype conventiblefto "fix'edpr'roftary wing operation, a"; vpai rwof rotary lifting surfaces rotating in opposite directions, a separate means for each of said surfaces for varying the vertical lift thereof, a directional control surface and a single control element operatively connected with said direction-a1 control surface and with said separate control means for vertical lift for differentially changing the angles of incidence of the rotating surfaces and operating said directional control surface simultaneously. l

. 19. In an aircraft, a convertiblelifting surface operable either as a rotary surface or a fixed surface, a motor for starting said surface from rest. and means converting said motor into a brake for arresting the rotation of the surface upon conversion from rotaryto fixed surface operation and means for orienting and locking said surface in fixed position including means for reversing the operation of the motor to impart to the surface a reverse rotation.

20. In an aircraft having a wing mounted for operation either as a rotating wing or a fixed wing, the combination of a power unit capable of operation either as a power unit for starting the rotation of the wing from rest upon conversign to rotary Wing operation and also as rotalateral antral,

'"tion energy absorbing means for arresting the rotation upon conversion from rotary wing operation and means for converting said power unit from one type of operation tothe other while in 21. In an aircraft. having a wing mounted for operation either as a rotating wing or a fixed wing, the combination of a'power unit capable of 1 n operation either as a power unit for starting the rotation of the wing-from restand also as rotation energy absorbing means for arresting the rotatio-n upon conversion to and. from rotary wing operation and means for converting said power unit from one type of operation to-the other while in the air, said power unit comprising a fluid motor which for starting receives fluid pressure from a storage reservoir and for arresting ;;the rotation of the wing supplies fluid under pres- .sure to said reservoir.

:22. In an aircraft, a lifting surface mounted for operation either as a fixedsurface or as a rotating surface, means for locking said lifting surface and each of said members firmly locking said lifting surface against rotation in one direction, one of said members also having a lost motion connection with its pivot,

I 24, Inan aircraft, a single centrally positioned convertible lifting ,surface, operable either as, a fixed wing'surface or as a rotating surface and having wing halves variable in angle of incidence, a control member operativelyconnected to, vary the angle of incidence of said halves in such manner that when said surface is rotating the lift of 'said halves is varied equally toachieve vertical control and when said surface isfixed the lift of said halvesis varied oppositely to achieve '28 -25. In an aircraft, a-sin'gle-gcentrally-positioned convertible lifting. surfaceoperable:leither asa fixed wing surface or as arotary wing surface and having halves'variable inangle of incidence, meansforperiodically varying the angle of incidence in.rotary-wingoperation, and a control member .operatively connected to said means, whereby infixed-wing'operationsaid control member variesthe angle-of incidence of said halvesequally forelevational controL- iiGERARD P. HERRICK.

mr fiti n il'TED t The following references are of record the flleof this patentf g STATES PATENTS H Number; Name Date 936,916 Lee 2 -2- :Oct, 12, 1909 1,049,927-:.:;. Sieg; --Jan. :7, 1918 1,272,846 Perry- I July-16,1918 1,419,363. Earle 1 June13, 1922 1,430,880 Benster Oct, 3,- 1922 1,446,531 William Feb. 27,- 1923 1,506,716,. Pescara, Aug.;26,. 1924 1,546,313 Pescara' July .14, 1925 1,557,739., Bane Oct.,20,' 1925 1,622,138 ..El1erman -.Mar..22,i 1'927 1,672,276. Nordberg June 5, 1928 1,792,014 Herrick Feb. 10, 1931 1,806,927 Aldrich May 26, 1931 1,823,417 Weber Sept. 15, 1931 1,877,902 Kuethe Sept. 30, 1932 1,900,689 I Baum Mar. '7, 1933 1,912,354 Pescara. May 30,1933 1,924,481 Bellanca Aug. 29, 1933 2,055,585 Perrin Sept. 29, 1936 2,076,327 Yurgen Apr. 6, 1937 2,088,413 Hafner July 27, 1937 2,187,295 Alvistur Jan. 16, 1940 2,256,635 Young Sept. 23, 1941 2,256,918 .Young Sept. 23, 1941 2,322,715 Kloeren June 22, 1943 2,340,241 Woods Jan. 25, 1944 2,383,139 McGuire Aug. 21, 1945 FOREIGN PATENTS Number 5 Country Date 640,875 France 'Apr. 7, 1928 

